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<h1>Module <code>pl.comprehension</code></h1>
<p>List comprehensions implemented in Lua.</p>
<p> See the <a href="http://lua-users.org/wiki/ListComprehensions">wiki page</a></p>


<pre>
<span class="keyword">local</span> C= <span class="global">require</span> <span class="string">'pl.comprehension'</span> . new()

C (<span class="string">'x for x=1,10'</span>) ()
==&gt; {<span class="number">1</span>,<span class="number">2</span>,<span class="number">3</span>,<span class="number">4</span>,<span class="number">5</span>,<span class="number">6</span>,<span class="number">7</span>,<span class="number">8</span>,<span class="number">9</span>,<span class="number">10</span>}
C <span class="string">'x^2 for x=1,4'</span> ()
==&gt; {<span class="number">1</span>,<span class="number">4</span>,<span class="number">9</span>,<span class="number">16</span>}
C <span class="string">'{x,x^2} for x=1,4'</span> ()
==&gt; {{<span class="number">1</span>,<span class="number">1</span>},{<span class="number">2</span>,<span class="number">4</span>},{<span class="number">3</span>,<span class="number">9</span>},{<span class="number">4</span>,<span class="number">16</span>}}
C <span class="string">'2*x for x'</span> {<span class="number">1</span>,<span class="number">2</span>,<span class="number">3</span>}
==&gt; {<span class="number">2</span>,<span class="number">4</span>,<span class="number">6</span>}
dbl = C <span class="string">'2*x for x'</span>
dbl {<span class="number">10</span>,<span class="number">20</span>,<span class="number">30</span>}
==&gt; {<span class="number">20</span>,<span class="number">40</span>,<span class="number">60</span>}
C <span class="string">'x for x if x % 2 == 0'</span> {<span class="number">1</span>,<span class="number">2</span>,<span class="number">3</span>,<span class="number">4</span>,<span class="number">5</span>}
==&gt; {<span class="number">2</span>,<span class="number">4</span>}
C <span class="string">'{x,y} for x = 1,2 for y = 1,2'</span> ()
==&gt; {{<span class="number">1</span>,<span class="number">1</span>},{<span class="number">1</span>,<span class="number">2</span>},{<span class="number">2</span>,<span class="number">1</span>},{<span class="number">2</span>,<span class="number">2</span>}}
C <span class="string">'{x,y} for x for y'</span> ({<span class="number">1</span>,<span class="number">2</span>},{<span class="number">10</span>,<span class="number">20</span>})
==&gt; {{<span class="number">1</span>,<span class="number">10</span>},{<span class="number">1</span>,<span class="number">20</span>},{<span class="number">2</span>,<span class="number">10</span>},{<span class="number">2</span>,<span class="number">20</span>}}
<span class="global">assert</span>(C <span class="string">'sum(x^2 for x)'</span> {<span class="number">2</span>,<span class="number">3</span>,<span class="number">4</span>} == <span class="number">2</span>^<span class="number">2</span>+<span class="number">3</span>^<span class="number">2</span>+<span class="number">4</span>^<span class="number">2</span>)
</pre>

<p> (c) 2008 David Manura. Licensed under the same terms as Lua (MIT license).</p>

<p> Dependencies: <a href="../libraries/pl.utils.html#">pl.utils</a>, <a href="../libraries/pl.luabalanced.html#">pl.luabalanced</a></p>

<p> See <a href="../manual/07-functional.md.html#List_Comprehensions">the Guide</a></p>



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